Vertebrate assemblages from the Junggar Basin in Xinjiang, China are the only ones known from palaeoarctic continental strata of Late Triassic and Early Jurassic age. Here we present a preliminary description of these new assemblages, focusing on the underappreciated Arctic palaeolatitude and winter freezing of this coal-bearing sequence. Mostly collected during NIGPAS-led stratigraphic studies in the 2016-2017 field seasons, new assemblages include: 1) small to large, sculptured palaeonisciform cranial elements and scales, small associated palaeonisciforms, a sauropterygian tooth, large-dinosaur bioturbation, and additional as yet unidentified small vertebrate bones from the Haojiagou Formation (?late Norian-Rhaetian); 2) a medium-sized brontozoid dinosaur footprint and a previously described possible
Anomoepus
track from the Badaowan Formation (Hettangian-?Pliensbachian); and 3) a hybodont shark egg case of the form taxon
Palaeoxyris
(only the third reported from the Early Jurassic of China), numerous associated and fragmentary small palaeonisciform remains including one partial skull and several small skeletons, and another possible
Anomoepus
track and associated dinoturbation from the Sangonghe Formation (?Pliensbachian-Toarcian). A possible ash associated with the aforementioned lower Sangonghe fish skull has produced a LA-ICP-MS age of roughly 186 Ma, consistent with a Pliensbachian age. We are optimistic that there will be many additional discoveries in early Mesozoic strata of the Junggar Basin, the importance of which for understanding Earth system processes cannot be overemphasised.
Supplementary material at
https://doi.org/10.6084/m9.figshare.c.6729761